Control method for idling anti-rollback of pure electric vehicle

ABSTRACT

The present invention relates to a control method for idling anti-rollback of pure electric vehicle, which comprises the following steps: determining whether an anti-rollback control is needed by the current state of the vehicle or not with the vehicle controller according to the brake pedal, the handbrake device and the accelerator pedal; If needed, judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller; If not satisfied, stopping the motor to output a torque; If satisfied, driving the motor to output the torque for the anti-rollback control. With this pure electric vehicle, the control method for idling anti-rollback of pure electric vehicle can be suitable for the pure electric vehicle, the pure electric vehicle uses the motor alone to drive the vehicle, therefore is very different from conventional cars in the control of the torque and the speed regulation, thus the present invention can be suitable for starting an electric vehicle at idle, prevents effectively an electric vehicle on a slope from rolling back, has a simple and quick processing procedure, and a stable and reliable performance, and lays a solid foundation for further development and application of the electric vehicle technology.

FIELD OF TECHNOLOGY

The present invention relates to the technical field of pure electric vehicle, especially to the technical field of idling power control of pure electric vehicle, in particular to a control method for idling anti-rollback of pure electric vehicle.

DESCRIPTION OF RELATED ARTS

Pure electric vehicle is a car whose power source is provided completely by rechargeable batteries (such as lead-acid batteries, nickel cadmium batteries, nickel metal hydride batteries or lithium ion batteries). The advantages of pure electric vehicle are that:

1. There is no pollution, and noise is low;

2. The structure is simple, and easy to use and maintain;

3. The energy conversion efficiency is high; at the same time the energy during braking and going downhill can be recycled, improving the energy utilization efficiency;

4. It can be charged at night using the cheap “valley point electricity” of the electric network, to play the role of stabilizing peak-valley difference of the electric network.

The use of electric vehicle can reduce effectively the dependence on the petroleum resources, and the limited petroleum can be used in more important aspects. Electric power used to charge storage batteries can be transformed by energy sources such as coal, natural gas, water power, nuclear energy, solar energy, wind power, tidal energy and so on. In addition, if storage batteries are charged at night, peak power demand can be kept away from, which is conducive to balance the load of the electric network and reduces costs. To the control of anti-rollback of traditional vehicle, the existing vehicle with automatic variable transmission comprises a torque convertor allowing the variable transmission to maintain putting into gear even if the vehicle stops or runs on a slope. In a vehicle with a variable transmission that does not have a torque convertor, such as the power shift variable transmission or the manual variable transmission, when the vehicle stops or runs on a slope, the clutch must slide or separate to prevent the vehicle from stalling, therefore the variable transmission can not transmit torques immediately to wheels.

When a vehicle with no torque converter climbs a positive slope from stopping on the slope, the delay when torques required to accelerate the vehicle are provided to wheels would cause undesirable vehicle rollback. When a driver presses down the accelerator pedal, known as “stepping on the accelerator pedal (tipiri)” and expects to climb the slope, the control of anti-rollback is needed. If torques are provided by the engine to the wheels to start the vehicle, delay would occur before the torques are transmitted to the wheels, due to the delay when the combustion air-fuel mixture inflates an inlet manifold and the engine cylinder, and the delay when the maximum torque transmitted from the variable transmission to the clutch is generated.

In the related art, there is a need for a method of eliminating undesirable rollback when a vehicle is on an uphill slope, and the driver releases the brake pedal and pulls down the handbrake, but does not step on the accelerator pedal and torques are not provided timely to the wheels of the vehicle.

SUMMARY OF THE INVENTION

Aspects of the present invention generally pertain to a control method for idling anti-rollback of pure electric vehicle, which can be suitable for starting an electric vehicle at idle, prevents effectively an electric vehicle on a slope from rolling back, and has a simple and quick processing procedure, and a stable and reliable performance, therefore the present invention is suitable for large-scale popularization.

In order to realize the above aims, the control method for idling anti-rollback of pure electric vehicle of the present invention is as follows:

The control method for idling anti-rollback of pure electric vehicle, wherein the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal and a power battery, the vehicle controller is connected with the motor controller, the brake pedal, the handbrake device, the accelerator pedal and the power battery, the power battery is connected with the motor through the motor controller, is characterized in that, the method comprises the following steps:

(1) Determining whether an anti-rollback control is needed by the current state of the vehicle or not with the vehicle controller according to the brake pedal, the handbrake device and the accelerator pedal;

(2) If needed, judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller;

(3) If not satisfied, controlling the motor controller with the vehicle controller to drive the motor to stop outputting a torque;

(4) If satisfied, controlling the motor controller with the vehicle controller to drive the motor to output the torque for the anti-rollback control.

In the control method for idling anti-rollback of pure electric vehicle, the step of determining whether an anti-rollback control is needed by the current state of the vehicle or not according to the brake pedal, the handbrake device and the accelerator pedal comprises the following steps:

(11) Determining whether the electric vehicle is located on a slope or not with the vehicle controller;

(12) If not, terminating the whole process; if yes, judging whether the handbrake device has been pulled down and the brake pedal is released or not with the vehicle controller;

(13) If not, braking the vehicle, and terminating the whole process; if yes, judging whether the position of the accelerator pedal is larger than a preset reference position or not with the vehicle controller;

(14) If yes, driving the vehicle normally, and terminating the whole process; if not, returning the result of needing the anti-rollback control.

In the control method for idling anti-rollback of pure electric vehicle, the step of judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller comprises the following steps:

(21) Detecting whether the electric quantity state of the power battery is higher than a preset reference electric quantity state or not with the vehicle controller;

(22) If not, returning the result of the working condition of the anti-rollback control being not satisfied;

(23) If yes, detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller;

(24) If not, returning the result of the working condition of the anti-rollback control being not satisfied;

(25) If yes, returning the result of the working condition of the anti-rollback control being satisfied.

In the control method for idling anti-rollback of pure electric vehicle, the power battery is a single battery, before detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller, the method further comprises the following steps:

(231) Detecting whether the voltage of the single battery is higher than a preset reference voltage or not with the vehicle controller;

(232) If not, returning to the step (24) directly;

(233) If yes, continuing the subsequent process in the step (23).

In the control method for idling anti-rollback of pure electric vehicle, the step of controlling the motor controller with the vehicle controller to drive the motor to output the torque for the anti-rollback control comprises the following steps:

(41) Driving the motor with the motor controller to generate the amount of the torque required by the anti-rollback control gradually;

(42) Continuing with the motor to increase the amount of the torque of the motor, so as to drive the vehicle to forward slowly;

(43) Adjusting the amount of the torque gradually with the vehicle controller, so as to maintain the idle speed of the vehicle.

With the control method for idling anti-rollback of pure electric vehicle, for the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal and a power battery, the method of the present invention makes cleverly use of the differences of the pure electric vehicle from conventional cars, collects the states of individual parts of the vehicle through the vehicle controller, controls the output of the torque of the motor based on the state information of various control components, to prevent the vehicle located on a slope from rolling back, and make the vehicle move forward at idle, therefore the present invention can be suitable for the pure electric vehicle, compared with conventional cars, the pure electric vehicle can use the motor alone to drive the vehicle, therefore is very different from conventional cars in the control of the torque and the speed regulation, thus the present invention can be suitable for starting an electric vehicle at idle, prevents effectively an electric vehicle on a slope from rolling back, has a simple and quick processing procedure, and a stable and reliable performance, and lays a solid foundation for further development and application of the electric vehicle technology.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of the structure of the functional modules of the pure electric vehicle of the present invention.

FIG. 2 is a flowchart of the control method for idling anti-rollback of pure electric vehicle of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

In order to understand the technical content of the present invention clearly, the present invention is further exemplified by reference to the following examples.

Please refer to FIG. 1-2, the control method for idling anti-rollback of pure electric vehicle, wherein the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal and a power battery, the vehicle controller is connected with the motor controller, the brake pedal, the handbrake device, the accelerator pedal and the power battery, the power battery is connected with the motor through the motor controller, is characterized in that, the method comprises the following steps:

(1) Determining whether an anti-rollback control is needed by the current state of the vehicle or not with the vehicle controller according to the brake pedal, the handbrake device and the accelerator pedal, which comprises the following steps;

(a) Determining whether the electric vehicle is located on a slope or not with the vehicle controller;

(b) If not, terminating the whole process; if yes, judging whether the handbrake device has been pulled down and the brake pedal is released or not with the vehicle controller;

(c) If not, braking the vehicle, and terminating the whole process; if yes, judging whether the position of the accelerator pedal is larger than a preset reference position or not with the vehicle controller;

(d) If yes, driving the vehicle normally, and terminating the whole process; if not, returning the result of needing the anti-rollback control;

(2) If needed, judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller, which comprises the following steps;

(a) Detecting whether the electric quantity state of the power battery is higher than a preset reference electric quantity state or not with the vehicle controller;

(b If not, returning the result of the working condition of the anti-rollback control being not satisfied;

(c) If yes, detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller, wherein before detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller, the method further comprises the following steps:

(i) Detecting whether the voltage of the single battery is higher than a preset reference voltage or not with the vehicle controller;

(ii) If not, returning to the step (24) directly;

(iii) If yes, continuing the subsequent process in the step (23);

(d) If not, returning the result of the working condition of the anti-rollback control being not satisfied;

(e) If yes, returning the result of the working condition of the anti-rollback control being satisfied.

(3) If not satisfied, controlling the motor controller with the vehicle controller to drive the motor to stop outputting a torque;

(4) If satisfied, controlling the motor controller with the vehicle controller to drive the motor to output the torque for the anti-rollback control, which comprises the following steps:

(a) Driving the motor with the motor controller to generate the amount of the torque required by the anti-rollback control graduall;

(b) Continuing with the motor to increase the amount of the torque of the motor, so as to drive the vehicle to forward slowly;

(c) Adjusting the amount of the torque gradually with the vehicle controller, so as to maintain the idle speed of the vehicle.

In actual use, the control method for idling anti-rollback of pure electric vehicle of the present invention, wherein the pure electric vehicle comprises a combined control of a vehicle controller (VCU), a motor controller (MCU), a motor, a brake pedal, a handbrake, an accelerator pedal and a power battery, and the method comprises the following steps:

a, Using the vehicle controller to determine the current state of the vehicle, whether there has a state of braking or a state of pulling up the handbrake;

b. Using the motor to gradually produce the amount of the torque required for anti-rollback;

c, Continuing to increase the amount of the torque of the motor, to make the vehicle move forward slowly; and

d, Using the vehicle controller to regulate the amount of the torque gradually to maintain the idle speed.

Wherein, the step a further comprises using the positions of the brake pedal and the handbrake to determine the current state of the vehicle.

the step a further comprises determining the position of the accelerator pedal, to determine the driver's intention.

(1) The vehicle controller is responsible for adjustingt and controlling the torque of the vehicle, the vehicle further comprises a battery for supplying electric power to the motor, and the method further comprises the following steps:

Determining whether the electric quantity state of the power battery is higher than a preset reference electric quantity state or not;

If the electric quantity state of the power battery is higher than the preset reference electric quantity state, using the motor to produce the torque required, to prevent the vehicle from rolling back, and move the vehicle forward at idle; and

If the electric quantity state of the power battery is lower than the preset reference electric quantity state, stopping outputting the torque.

(2) The vehicle further comprises a single battery for supplying electric power to the motor, and the method further comprises the following steps:

Determining whether the electric quantity state of the single battery is higher than a preset reference electric quantity state or not;

If the electric quantity state of the single battery is higher than the preset reference electric quantity state, using the motor to produce the torque required, to prevent the vehicle from rolling back, and move the vehicle forward at idle; and

If the electric quantity state of the single battery is lower than the preset reference electric quantity state, stopping outputting the torque.

(3) The method further comprises the following steps:

Determining whether the temperature of the motor and the motor controller are lower than a preset reference temperature or not;

If the temperature of the motor is lower than the reference temperature, using the motor to produce the desired torque, to prevent the vehicle from rolling back, and move the vehicle forward at idle; and

If the temperature of the motor is higher than the reference temperature. stopping outputting the torque.

The vehicle controller is responsible for collecting the state information of the battery, the motor and the motor controller.

Please refer to FIG. 1, the vehicle power system comprises a vehicle controller, a motor controller, a motor, an accelerator pedal, a brake pedal, a handbrake and a power battery. The vehicle controller is responsible for collecting the working states of various control components, and determines the working mode of the motor according to the working states of various components, and adjusts the motor to output the torque, to prevent the vehicle on the slope from rolling back, and can move the vehicle forward at idle.

Then please refer to FIG. 2, which is a control flow for preventing an electric vehicle located on a steep slope from rolling back. When the electric vehicle is located on a slope, the vehicle controller first determines the intention of the driver, whether starting the vehicle is needed, i.e. judges whether the handbrake is pulled down or not and whether the brake pedal is released or not, when the handbrake is still in the pulling up state or the brake pedal is in the braking state, the vehicle controller stops outputting the torque, and maintains the current states, if the handbrake is in the pulling down state and the brake pedal is in the releasing state, the vehicle controller judges the electric quantity state of the battery and the temperature situation of the motor and its controller, when the electric quantity of the battery is higher than the reference electric quantity, the single voltage is higher than the reference voltage, and the temperature of the motor and its controller is lower than the reference temperature, the motor is adjusted to output the torque, to prevent the vehicle from rolling back and move the vehicle forward at idle. Otherwise, the torque is stopped to output and a buzzing sound is made to remind the driver to brake the vehicle, so as to protect the motor and its controller, and the power battery;

In the stage of the vehicle controller adjusting the motor to output the torque, when the accelerator pedal exceeds the reference value, and the accelerator pedal works, the controller exits the anti-rollback idling mode, and enters into the normal running mode.

With the control method for idling anti-rollback of pure electric vehicle, for the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal and a power battery, the method of the present invention makes cleverly use of the differences of the pure electric vehicle from conventional cars, collects the states of individual parts of the vehicle through the vehicle controller, controls the output of the torque of the motor based on the state information of various control components, to prevent the vehicle located on a slope from rolling back, and make the vehicle move forward at idle, therefore the present invention can be suitable for the pure electric vehicle, compared with conventional cars, the pure electric vehicle can use the motor alone to drive the vehicle, therefore is very different from conventional cars in the control of the torque and the speed regulation, thus the present invention can be suitable for starting an electric vehicle at idle, prevents effectively an electric vehicle on a slope from rolling back, has a simple and quick processing procedure, and a stable and reliable performance, and lays a solid foundation for further development and application of the electric vehicle technology.

In the present specification, the present invention has been described according to the particular embodiments. But it is obvious that these embodiments can be modified or changed without departure from the spirit and scope of the present invention. Therefore, the specification and drawings described above are exemplary only and not intended to be limiting. 

I claim:
 1. A control method for idling anti-rollback of pure electric vehicle, wherein the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal and a power battery, the vehicle controller is connected with the motor controller, the brake pedal, the handbrake device, the accelerator pedal and the power battery, the power battery is connected with the motor through the motor controller, characterized in that, the method comprises the following steps: (1) Determining whether an anti-rollback control is needed by the current state of the vehicle or not with the vehicle controller according to the brake pedal, the handbrake device and the accelerator pedal; (2) If needed, judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller (3) If not satisfied, controlling the motor controller with the vehicle controller to drive the motor to stop outputting a torque; (4) If satisfied, controlling the motor controller with the vehicle controller to drive the motor to output the torque for the anti-rollback control.
 2. The control method for idling anti-rollback of pure electric vehicle according to claim 1, characterized in that, the step of determining whether an anti-rollback control is needed by the current state of the vehicle or not according to the brake pedal, the handbrake device and the accelerator pedal comprises the following steps: (11) Determining whether the electric vehicle is located on a slope or not with the vehicle controller; (12) If not, terminating the whole process; if yes, judging whether the handbrake device has been pulled down and the brake pedal is released or not with the vehicle controller; (13) If not, braking the vehicle, and terminating the whole process; if yes, judging whether the position of the accelerator pedal is larger than a preset reference position or not with the vehicle controller; (14) If yes, driving the vehicle normally, and terminating the whole process; if not, returning the result of needing the anti-rollback control.
 3. The control method for idling anti-rollback of pure electric vehicle according to claim 1, characterized in that, the step of judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller comprises the following steps: (21) Detecting whether the electric quantity state of the power battery is higher than a preset reference electric quantity state or not with the vehicle controller; (22) If not, returning the result of the working condition of the anti-rollback control being not satisfied; (23) If yes, detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller; (24) If not, returning the result of the working condition of the anti-rollback control being not satisfied; (25) If yes, returning the result of the working condition of the anti-rollback control being satisfied.
 4. The control method for idling anti-rollback of pure electric vehicle according to claim 3, characterized in that, the power battery is a single battery, before detecting whether the temperature of the motor and the motor controller is lower than a preset reference temperature or not with the vehicle controller, the method further comprises the following steps: (231) Detecting whether the voltage of the single battery is higher than a preset reference voltage or not with the vehicle controller; (232) If not, returning to the step (24) directly; (233) If yes, continuing the subsequent process in the step (23).
 5. The control method for idling anti-rollback of pure electric vehicle according to claim 1, characterized in that, the step of controlling the motor controller with the vehicle controller to drive the motor to output the torque for the anti-rollback control comprises the following steps: (41) Driving the motor with the motor controller to generate the amount of the torque required by the anti-rollback control gradually; (42) Continuing with the motor to increase the amount of the torque of the motor, so as to drive the vehicle to forward slowly; (43) Adjusting the amount of the torque gradually with the vehicle controller, so as to maintain the idle speed of the vehicle. 